<p style="font-weight:bold;">{$operator} 转移了任务</p>
<div style="color:#aaa;"><p>{$log_detail_info['category_id']['old_value']}</p></div>
  <p style="font-weight:bold;">修改为:</p>
  <p style="color:green;">{$log_detail_info['category_id']['new_value']}</p>